Google Drive API - List folders and download images inside

index.js

import { google } from 'googleapis';
import * as fs from 'fs';

function authGoogleApi() {
    let auth = new google.auth.GoogleAuth({
        keyFile: './service-account.json',
        scopes: [
            'https://www.googleapis.com/auth/drive.readonly',
        ],
    });
    return auth;
}

const drive = google.drive({ version: 'v3', auth: authGoogleApi() });

const folderId = '{Root Folder ID}';

const res = await drive.files
    .get({ fileId: folderId })
    .catch((err) => console.log(err.errors));

var query =
    "'" +
    folderId +
    "' in parents and trashed = false";
drive.files.list(
    {
        q: query,
        fields: "files(id, name)",
    },
    async function (error, response) {
        if (error) {
            return console.log("ERROR", error);
        }

        for (var folder of response.data.files) {

            const res = await drive.files
                .get({ fileId: folder.id })
                .catch((err) => console.log(err.errors));
            const folderName = res.data.name;

            if (!fs.existsSync("./img/" + folderName)) {
                fs.mkdirSync("./img/" + folderName);
            }

            var query =
                "'" +
                folder.id +
                "' in parents and mimeType contains 'image/' and trashed = false";
            drive.files.list(
                {
                    q: query,
                    fields: "files(id, name)",
                },
                function (error, response) {
                    if (error) {
                        return console.log("ERROR", error);
                    }

                    response.data.files.forEach(function (item) {
                        var file = fs.createWriteStream("./img/" + folderName + "/" + item.id + " - " + item.name);
                        file.on("finish", function () {
                            console.log("downloaded", item.name);
                        });

                        // Download file
                        drive.files.get(
                            {
                                fileId: item.id,
                                alt: "media",
                            },
                            {
                                responseType: "stream",
                            },
                            function (err, response) {
                                if (err) return "";

                                response.data
                                    .on("error", (err) => { })
                                    .on("end", () => { })
                                    .pipe(file);
                            }
                        );
                    });
                }
            );
        }

    }
);